This is kind of a vague question which makes it a bit tricky to answer. What kind of website audit are you performing?

The different types of website audits that I've done for myself and others include

• Content Auditing - this can include everything for removing / purging old content to checking that the content reflects the voice and image of the brand.
• Usability Auditing - looking for areas of the website that lack visual hierarchy, confusing information / terminology, misleading links, navigation issues, more
• Cross Browser Auditing - checking the same website across a variety of popular browsers to look for any issues in a specific browser or issues that are across all browsers
• Cross Device Auditing - similar to Cross Browser, but focused on checking how website looks across multiple devices (different sizes, different operating systems, etc.). This is also important for testing your "responsive" and/or "adaptive" web designs.
• Link Auditing - this is related to content auditing but focuses specifically on identifying dead links (links that no longer arrive at intended content), incorrectly linked items (pointing to the wrong destination) or items that should be links but currently aren't.
• Performance Auditing - this is all about how fast does your content load and looking for places of improvement such as, minifying files (CSS and/or JavaScript), condensing images (either changing image formats from JPG to PNG or GIF), reducing image load times (putting many images into one (AKA an image "sprite"), using content delivery networks (CDNs) instead of hosting all information on your own site and removing unnecessary content and plugins.
• Security Auditing - obviously an important one. Ensure admin passwords you use are strong and kept in secure places. Ensure content management systems (CMSs) you use are as up to date as possible. Add front-end and back-end form (input) validation to eliminate people trying to inject code that could hijack, overload or wipe out your data/system.
• Traffic Auditing - this is more about understanding (and having) analytics. Do you know what is driving people to your website? Do you know when people are coming to your website? Do you know where your main sources of traffic are coming from? Seeing anomalies can make you revisit your Security Auditing (such as do you see many IP addresses visiting your site from countries known for hacking?).

These are the main types of website audits I know about and have conducted. Have I missed any other types of audits? I hope this information was at least a good starting point for you.